REAL-ADHERE · Grant No. 101285102 · SURFACE · Grant No. 101039198 · Horizon Europe

Neural prediction of rate-dependent adhesive contact

An interactive, browser-based scientific demonstrator for exploring the force response of a rigid sphere in adhesive contact with a linear viscoelastic substrate under a loading–dwell–unloading protocol.

This demonstrator accompanies the study

Deep learning-based prediction of time-resolved adhesive forces in viscoelastic Hertzian contacts

Ali Maghamia,b, Merten Stenderb, Michele Ciavarellaa, Antonio Papangeloa

a TriboDynamics Lab, Department of Mechanics, Mathematics and Management, Polytechnic University of Bari, Via Orabona 4, Bari 70125, Italy
b Chair of Cyber-Physical Systems in Mechanical Engineering, Technische Universität Berlin, Straße des 17. Juni, Berlin 10623, Germany

01 · Physical system

History-dependent viscoelastic adhesive contact

The physical problem is the axisymmetric adhesive contact between a rigid sphere and a linear-viscoelastic half-space. A finite-range Lennard–Jones traction–separation law acts across the evolving gap, while viscoelastic memory makes the normal force depend on the complete prescribed displacement history rather than on the instantaneous indentation alone. The loading–dwell–unloading protocol therefore couples approach, relaxation at fixed indentation, and detachment; its force trajectory is governed jointly by the loading and unloading rates, dwell time, peak indentation, adhesion range, and contact modulus.

Two vector panels: panel a shows a rigid sphere of radius R above a viscoelastic substrate with interaction range h0, and panel b defines the axisymmetric geometric gap h of radial coordinate r and time t.
Physical and geometric definition. (a) Rigid sphere and linear viscoelastic substrate with a finite-range adhesive interaction. (b) Axisymmetric gap h(r, t) between the undeformed sphere profile and substrate displacement. Vector excerpt derived from Figure 1 of the underlying study.
R
sphere radius
δ(t)
prescribed indentation
h0
equilibrium interaction range
h(r, t)
local interfacial gap
uz(r, t)
history-dependent substrate displacement
r, t
radial coordinate and time

02 · Dimensionless formulation

One surrogate, physically similar systems

Dimensionless variables remove the particular unit scale, allowing the surrogate to represent systems that share the same reduced physics.

Reduced protocol and force

δ = δh0 t = tτr v = rh0 P = PπΔγ0R

τr is the viscoelastic relaxation time; hats denote dimensionless quantities.

Adhesion-range regime

μ is the dimensionless Tabor parameter controlling the transition from long-range/DMT-like to short-range/JKR-like adhesion.

μ = 3RΔγ02E*²h03 E* = E1 − ν2

R is sphere radius, Δγ0 thermodynamic surface energy, h0 interaction range, and E* contact modulus.

03 · Interactive M1-concat surrogate

Define one virtual experiment

Enter the five parameters in the order reported in Table 1. The defaults reproduce sample 11. Prediction runs entirely on your device; values are never uploaded or stored.

Initialising browser inference…
Backend: detecting
documented 0.1–1000
documented 0.001–3
documented 0.1–1000
documented 0.2–3.2
documented 0–100
Awaiting protocol

Support score will appear after prediction.

1

Displacement protocol

120 measurement steps with phase-resolved support

Enter a protocol and select Predict.

2

Neural surrogate

Actual M1-concat architecture

3

Predicted response

Figure 6-style force–indentation trajectory

The Figure 6-style prediction will appear here.

04 · Model provenance

Reproducible browser inference

The published bundle contains the original HDF5 model, its TensorFlow.js conversion, exact preprocessing scalers, and browser-safe support metadata. It does not contain raw training force trajectories.

ArchitectureLSTM 256 → LSTM 128 → TD Dense 64
Input120 × 4 sequence + μ
ExecutionTensorFlow.js · WebGL / CPU
PrivacyNo backend · no analytics · no uploads

05 · Scientific foundations

Related work and citation

This demonstrator builds on the theoretical, numerical, and machine-learning studies listed below. If you use its scientific ideas, model, data, or visualisations in scholarly work, please cite the relevant publications in addition to this demonstrator.

  1. Maghami, A.; Stender, M.; Papangelo, A.Pull-off force prediction in viscoelastic adhesive Hertzian contact by physics augmented machine learning.International Journal of Solids and Structures 322, 113584.DOI: 10.1016/j.ijsolstr.2025.113584
  2. Maghami, A.; Wang, Q.; Tricarico, M.; Ciavarella, M.; Li, Q.; Papangelo, A.Bulk and fracture process zone contribution to the rate-dependent adhesion amplification in viscoelastic broad-band materials.Journal of the Mechanics and Physics of Solids 193, 105844.DOI: 10.1016/j.jmps.2024.105844